Access to a rooftop is a luxury of city living. It's no surprise that today's bars, restaurants, hotels, and apartment buildings are all racing to cash in on the human impulse to climb to the tops of things and hang out there. But 140 years ago, the only thing that hung out on urban roofs was wet laundry. Back then, rooftops were the exclusive domain of industrial equipment and domestic servants. The impulse of most residents was to stay away.

The American dream of private home ownership was well established in the 1870s, when developers first began to invest in apartment houses for the rising urban classes. But middle-class Americans were still nervous about the notion of living on top of their neighbors—they distrusted the diminishment of private space that this arrangement seemed to create. Apartment buildings of the time were specifically designed to alleviate this 19th century awkwardness with elements like private entrances and carefully placed staircases and hallways, to limit the possibility of actually running into a neighbor. Balconies were rare, as they were negatively associated being too public and with working-class immigrant housing.

In the 1880s, Rudolph Aronson, a New York conductor and musician, took a trip to Europe where he experienced something of a revelation: urban gardens where summertime audiences gathered to enjoy musical and theatrical performances. He returned to New York determined to recreate one in his own image. Space in Manhattan was at a premium even then, and so instead of a traditional street-level garden, Aronson perched his on the roof of his newly built Moorish-styled Casino Theatre on Broadway. With no air-conditioning, the stifling theaters were inhospitable places for summertime entertainment. Now, Aronson could comfortably stage operettas, musicals and concerts on his roof.

Other theaters took note and roof gardens blossomed in New York, where they centered around the bustling Broadway theater district. Variety acts would perform on lavish stage sets under thousands of electric lights, surrounded by palm trees, or amid a recreated Dutch farm complete with a windmill and live cows (available for the milking).

The gardens became a place of escape from the din and heat of the city, and reproduced (not always accurately) exotic locales, effecting a kind of rooftop summer staycation for the 19th century urban bon vivant. The roof of the original Madison Square Garden, built in 1890, was designed as an Italian pleasure garden with a 300-foot neo-Renaissance bell tower. Another theater roof was outfitted as a rustic alpine village complete with swan pond, grottoes and a 10-foot tall fake craggy mountainside.

From the 1880s until the end of century, extravagant theater rooftop gardens became a staple of summertime entertainment in major cities across the country, attracting thousands of pleasure-seekers for raucous evenings under the starless urban sky. The experience was even put to music: “The Roof Garden Two-Step” was a popular dance number in 1885. At Chicago’s Masonic Temple Roof Theatre, the bill of fare promised “Refined high class vaudeville” at the 25-cent matinée with such acts as “Up-To-Date Laugh-Makers” and the spectacle of “Head to Head to Hand to Hand Balancers.” During intermission, theatergoers were encouraged to take a stroll on the roof’s promenade.

The rooftop parties raged on until changing tastes and technology ultimately won out. The types of light entertainment offered both on theater roofs and at ground level were eventually replaced by moving pictures in the 1920s. One after another, live stages closed or were converted into movie palaces. But the legacy of socializing on roofs lived on through restaurants, hotels, and apartment buildings.

As buildings began to grow ever taller with the advent of the elevator, height became the status symbol of the new urban rich. Grand apartment buildings came with grand views and rooftops were developed to take full advantage of them. Laundry equipment moved to the basement, and elevators conveyed tenants up to the fresh air and city vistas.

Elevators also effectively switched the value of apartments. Once top-floor apartments attracted lower rents due to the exhaustive climb and proximity to the rooftop service space. Suddenly these quieter and sunnier apartments were easily accessible and thus more valuable. As the penthouse became the ultimate symbol of urban achievement, it also functioned as a distancing mechanism between the classes. The crowded city no longer separated its rich and poor laterally by neighborhood, but rather vertically by structure. Mighty new urban kings could now sit upon their rooftop thrones gazing down on the masses below.

Although the popularity of theater roof gardens gradually dwindled after the turn of the century, rooftop dining and dancing remained a surefire way to draw in crowds at high-end hotels in the 1920s and 1930s, like at the Waldorf-Astoria and Astor hotels in New York and the Powhatan Hotel in Washington, D.C. New hotels bit by the al fresco bug tended to construct roof gardens even more theatrical than their predecessors, offering dinner, drinks, music and dancing among dramatic fountains, vine-covered pergolas, topiaries, and wisteria groves.

Ambitious new public developments became increasingly rare during the depression. Yet in the 1930s and 1940s, two influential large-scale projects with rooftop gardens came into being: Rockefeller Center in New York and San Francisco’s Union Square, which sits atop a garage. As attention shifted to constructing new housing and small-scale commercial structures after the war, and as air conditioning became more commonplace, the impetus to invest in rooftops waned. But some modernist architects were already seeking to reverse this trend. Le Corbusier considered the roof garden to be a central element of modern architecture—a “free zone” where nature could be reclaimed in a controlled way, as an extension of the interior.

In the 1960s, one notable large-scale project ushered in a new era of roof gardens: the Kaiser Center in Oakland, California. Stretching 3.5 acres atop a five-story parking garage with large trees, reflecting pools, walkways and benches, the garden remains an exemplar of rooftop design that helped to reawaken Americans' taste for rooftop development.

These days, it's practically illegal to put up a new luxury apartment building without the expected roofdeck lounge (and it might actually be illegal to hang your laundry up there now). The last decade has indeed seen something of a rooftop renaissance. From luxury decks and penthouses, to sustainable green roofs and farms, roofs are valuable and diverse real estate that hold both profit potential and ecological benefits.

There are 20,000 acres of usable roofs in New York City alone (that’s 23 times the size of Central Park). Transforming any one of them into a green roof, with a drainage system and the necessary engineering structures to grow plants, is mostly a matter of weight and water. In 2000, the city of Chicago transformed the roof of its neoclassical city hall into a 23,000 square-foot green roof in an ambitious effort to encourage Chicagoans to redevelop their own rooftops and help reduce city temperatures and energy costs. In Germany, where the sustainable green roof movement was born in the 1970s, several cities now require that certain new buildings include green roofs in their designs. None of this has been lost on commercial developers, thousands of whom have embraced the fact that installing a green roof will earn them nearly 40 percent of the necessary LEED points for coveted gold certification.

Hotels and restaurants too are designing their roofs to spectacular effect, rivaling the theater gardens of a century ago in sheer extravagance. Where once laundry dried, now drinks are doled out at $20 a pop. And maybe, as architecture critic Aaron Betsky has noted, the future will find us looking to build beyond the roof, with structures that will be “only a cloud, floating above the city.” If so, the future may have already arrived, and it’s in Las Vegas. Dinner in the Sky allows thrill-seeking gastronomes to enjoy their aerial meals while suspended 180 feet above the Vegas Strip.